In recent years, a digital multifunctional peripheral (MFP) having a plurality of functions including a copy function, a printer function, a facsimile function, and a scanner function has become popular. The MFP is provided with a large document platen so that documents having up to A3 size can be read normally. When performing copy with this MFP, a user closes a document cover (document pressing plate) with a document set on the document platen to execute scanning.
At this time, the document cover is closed to hide the document so that the user can not visually view the document. Thus, the user can leave the document set on the document platen behind carelessly after obtaining a copy. Especially, when copying a relatively small-sized document, such as a driver's license, a name card and an L-sized picture, the document is often left behind without noticing the existence thereof.
Meanwhile, an input display in which a relatively small-sized liquid crystal panel has a function for reading a document placed on a screen in addition to a conventional display function for displaying image data on the screen attracts attention (for example, see Japanese Laid-Open Patent Publication No. 2006-179977). When this input display is mounted to a portable terminal such as a portable information terminal (PDA), a card-sized document can be easily read and information in the document can easily be obtained. Note that, as the input display an area sensor is generally employed. The area sensor captures an image of an object by a photoelectric conversion element provided on a plane as electric signal and therefore does not need to scan the photoelectric conversion element, that is different from a line sensor, and does not need a motor and the like for scanning.
An operation portion of the MFP is generally provided with a liquid crystal display portion with a touch panel in many cases and this portion is directly operated by a user, to which each user's attention is most likely to be directed. When the above-mentioned reading function is provided in the liquid crystal display portion, it is possible to read and capture a relatively small-sized document such as a driver's license. By employing such a structure, the convenience is improved as follows. First, it is not necessary to perform an operation of setting a document on a document platen, closing a document cover, and opening the document cover after reading the document image, thus making it possible to easily read the document image. Secondly, user's attention is most likely to be directed to the liquid crystal display portion, thus making it possible to prevent a document from being left behind.
However, the conventional art including the technique described in Japanese Laid-Open Patent Publication No. 2006-179977 does not assume the structure where the input display is incorporated in the MFP, resulting that the conventional MFP can not read a document on a liquid crystal display portion.
Furthermore, when the structure where the liquid crystal display portion of the MFP performs document reading is employed, although a user places a document on a document platen, the document can stick out from the document platen to extend over the liquid crystal display portion. In such a case, the area sensor of the liquid crystal display portion erroneously determines that the document is placed so that the area sensor reads an unnecessary document image.